Center for Research on Ingredient Safety

What are cooking oils?

Cooking oils are lipids (fats) made from plants, animals, or synthetic compounds used when frying, baking, and preparing foods for consumption. 
 
We find three lipids in cooking oils, triacylglycerols (also known as triglycerides), phospholipids, and sterols. Triacylglycerols are the most common lipid found in our foods. 
 
There are many oils. This blog post will focus on the most common cooking oils derived from plants and animals.

What is cooking oil made from? 

Cooking oils are typically derived from plants and animals. 
 
Plants often include 

• Avocados
• Canola Seeds
• Corn Kernels 
• Olives
• Palm Tree Kernels
• Peanuts
• Sesame Seeds
• Soybeans
• Sunflower Seeds 

Animal fat and animal products can be made into cooking oils. These can include 

• Butter 
• Lard (e.g., pork fat, duck fat, etc.) 
• Tallow (e.g., beef, mutton) 

How are cooking oils used? 

We use cooking oils in frying, baking, flavoring, sautéing, roasting, grilling, and more. 
 
We use cooking oils for many purposes, but often, the oils impart a flavor we’d like to incorporate into the foods we’re preparing. For example, a baked good that uses lard from an animal will have a different taste than a baked good that uses margarine made from a plant. 

Do I need cooking oils and fats in my diet to stay healthy?

We need fats in our diets to maintain our bodily functions. Fats provide the necessary building blocks to support hormone regulations, immune function, and bone, organ, and nerve development and maintenance. In short, we need fats to maintain our health. 
 
However, the fats in our diet don’t necessarily need to come from cooking oil. They can come from foods we eat, like nuts, fish, meat, and dairy products. 
 
Healthy fats found in many plant-based oils (e.g., olive oil, sunflower oil) can benefit our health. 

Do I need specific cooking oils?

Depending on what you’re making, you may need specific cooking oil to cook or prepare your food safely. 

Let’s look at frying foods. 

Cooking oils have different smoke points. Smoke points are the temperature at which a cooking oil begins to burn and is no longer suitable for use. If you don’t use an oil with the correct smoke point, you will risk not cooking your food correctly, burning your oil, or possibly creating a fire hazard. 

For example, when deep-fat frying foods, you need a cooking oil like peanut oil or canola oil with a high smoke point rather than an ingredient like olive oil with a lower smoke point.  

Do cooking oils expire? 

Just like other foods, cooking oils can go rancid if stored improperly or if they are too old. 
 
Different cooking oils will have different shelf lives. You can check out the shelf life of your favorite cooking oil on the USDA's Food Keeper App. 
 

What do I need to know about hydrogenated and partially hydrogenated cooking oils? Are all oils hydrogenated?

Cooking oils can go rancid. The process of hydrogenation adds hydrogen to the fats to increase their shelf life, so they remain safe in manufactured food products. 
 
We find hydrogenated oils in products like margarine and pre-packaged baked goods. The liquid plant-based oils we buy in the store for cooking are typically not hydrogenated. 
 
Partially hydrogenating vegetable oils create a solid fat at room temperature. Manufacturers used partially hydronated oils to create products like shortening that were found in many pre-packaged foods. These are known as trans fats. Since 2020, foods in the USA do not contain partially hydrogenated oils, and they are no longer generally recognized as safe (GRAS) ingredients by the FDA. 
 
We still have trans fats in our foods, but they are naturally occurring trans fats found in products like milk, butter, cheese, meat, and more. 
 

What is the difference between unsaturated and saturated fat in cooking oils? 

Unsaturated fats can help maintain our health without adversely impacting our cholesterol levels. We find unsaturated fats in many plant-based cooking oils that remain liquid at room temperature, like olive oil or avocado oil. 
 
Saturated fats in too large of quantities can adversely impact our cholesterol levels and overall health. We often find saturated fats in animal products like butter or tallow and plant-based oils that are solid at room temperate like coconut oil or palm oil.

The good news.

We have many options to choose from when it comes to using cooking oils. We also know that cooking oils, even those high in saturated fat, are safe when used in moderation. In our next post, we will dive deeper into plant-based cooking oils.